Sorry if I offended anyone in particular. The information I posted was from a site on renewable energy specifically geothermal energy. Of course I know that schist is metamorphic and that magma/lava is igneous.I was stating the fact that in the area of the geothermal power plants the process of returning the cooled water was cooling the metamorphic rock also in the same area.In its natural state undisturbed by man this metamorphic rock,under intense pressure is pliable and absorbs energy.Once it is cooled to a certain state it releases this energy.
Even data on the location,and depth of some of the micro-quakes are showing this to be a possibility.

• How Metamorphic Rock Is Formed